Atrial Natriuretic Peptide

OVERVIEW

• isolated from the right atrium
• 28 aa peptide
• potent diuretic/natriuretic effect on kidney + vasodilator effects on resistance & capacitance of blood vessels
• released in response to atrial stretching (ie. fluid overload)

FUNCTIONS

• vasodilation of afferent > efferent arterioles -> increased GFR
• increased urinary Na+ & H2O excretion
• relaxation of vascular smooth muscle -> vasodilation
• inhibition of plasma renin activity
• inhibition of aldosterone release
• inhibition of ADH secretion by post-pituitary

References and Links

• Witthaut R. Science review: natriuretic peptides in critical illness. Crit Care. 2004 Oct;8(5):342-9. Epub 2004 Jun 17. PMCID: PMC1065010.